Division of Compensation Analysis and 

Support 

Program Evaluation Report 

Document Number: DCAS-PER-092 

Effective Date: 03/29/2021 

Weldon Spring Plant Page 1 of 3 

Author: 

David Allen, HP Team Leader 

Signature on file Date: 03/23/2021 Supersedes: none 

Approval:

T. Taulbee, Associate Director for Science 

Signature on file Date: 03/29/2021

RECORD OF ISSUE/REVISIONS 

ISSUE 

AUTHORIZATION 

DATE 

EFFECTIVE 

DATE 

DESCRIPTION 

03/19/2021 03/29/2021 New document to determine the effect of 

issuing revision 4 to ORAUT-TKBS0028-4 (Weldon Spring Plant TBD, 

section 4) on previously completed 

claims. 

1.0 Description 

The Technical Basis Document (TBD) for the Weldon Spring Plant (ORAUT-TKBS0028) actually covers three facilities, the Weldon Springs Plant, the Weldon Spring 

Quarry and the Weldon Spring Raffinate Pits. For the purpose of this Program 

Evaluation Report (PER) all three are considered together and referred to as the Weldon 

Spring Plant (WSP). 

Revision 4 of the Environmental section of the TBD was issued on 3/27/2020. All other 

revisions to the Environmental section or other sections of the TBD were evaluated in a 

previous PER (DCAS-PER-083). Therefore, this PER will evaluate only the changes 

made in revision 4 of the Environmental section of the TBD. 

2.0 Issue Evaluation 

Increases in dose due to revision 4 of the TBD include the following issues. 

- Environmental intakes of Rn-220 and Ra-228 were added for 1963 through 1966. 
 

 

 

 

 

Division of Compensation Analysis and 

Support 

Program Evaluation Report 

Document Number: DCAS-PER-092 

Effective Date: 03/29/2021 Page 2 of 3 

- U-234 intakes were added for the Weldon Spring Quarry for the years 1990, 

1991, 1993-1996, and 1998-2001. 

- On-site ambient gamma doses from 1957 to 1966 were previously used as a 

constant value but revision 4 included GSD values and are used as a lognormal 

distribution. 

3.0 Plan for Resolving Corrective Action 

A search of the NIOSH Claims Tracking System (NOCTS) database was combined with 

a text search of the dose reconstruction reports of previously completed claims. The 

NOCTS search queried employment at any of the three Weldon Spring sites while the 

text search queried the keyword “Weldon Spring” so that mention of any of the three 

would be found. The combined search resulted in a total of 338 claims. 

The population of claims was reduced by first removing 50 claims that had been pulled 

from dose reconstruction. Most of these were pulled because they had met the criteria for 

compensation under the SEC prior to a dose reconstruction being completed. 

Next, 135 claims were removed because the original dose reconstructions resulted in a 

probability of causation greater than 50%. Therefore, no increase in dose would affect 

eligibility for compensation. 

One claim was removed because it had been returned for other reasons. As an active 

claim, it would be completed using the revised TBD and no further evaluation under this 

TBD was necessary. 

Seven claims were removed because they had no Weldon Spring employment or visits 

during the covered period. The claims were included in the original population because 

Weldon Spring was mentioned in the text of the dose reconstruction or the time frame 

they were present was not a covered period. 

An additional 90 claims were removed because they were not affected by the changes in 

the revised TBD primarily, those were monitored individuals for which no environmental 

dose was assigned. 

Lastly, one claim was removed because it met the requirements of an Special Exposure 

Cohort (SEC) so a revised dose reconstruction was not necessary for a compensation 

decision. 

Dose for the remaining 54 claims was recalculated using revision 4 of the TBD as well as 

all other applicable procedures. The resulting probability of causation for all 54 claims 
 

 

 

Division of Compensation Analysis and 

Support 

Program Evaluation Report 

Document Number: DCAS-PER-092 

Effective Date: 03/29/2021 Page 3 of 3 

was less than 45%. Therefore, none required additional IREP runs per NIOSH 

procedures. 

NIOSH will provide the Department of Labor with the list of all the claims evaluated 

under this PER. Since none of the claims resulted in a probability of causation greater 

than 50%, NIOSH will not request that the Department of Labor return any claims for a 

new dose reconstruction.